Auxiliary carburetor for internal combustion engines



July 29, 1958 MATRE 2,845,256

AUXILIARY'CARBURETQR FOR INTERNAL COMBUSTION ENGINES 2 Sheets-Sheet 1 Filed Sept. 16. 1955 ATTORNEYS July 29, 1958 F. G. VAN MATRE 2,845,256

AUXILIARY CARBURETOR FOR INTERNAL COMBUSTION ENGINES Filed Sept. 16. 1955 2 Sheets-Sheet 2 INVENTOR. Fred G. Van Moire ATTORNEYS United AUXILIARY CARBURETQR FOR COMBUSTION ENGINES Application September 16, 1955, Serial No. 534,721

Claims. (Cl. 261-72) This invention relates to improvements in auxiliary carburetors or fuel Vaporizers for internal combustion engines in which air is bubbled through a small reservoir of fuel so as to vaporize the fuel for introduction into a main carburetor system for the engine to thereby increase the efliciency of engine operation.

Auxiliary carburetors or fuel Vaporizers are well-known in the art, for example U. S. Patent No. 2,702,694, issued February 22, 1955, for Auxiliary Carburetor and Fuel Vaporizer for Internal Combustion Engines, to R. R. Featherstone, and also, copending application Serial No. 496,246, filed March 23, 1955, for Auxiliary Carburetors for Combustion Engines, by Robert H. Van Matre. In general, such auxiliary carburetors include a small reservoir for the liquid fuel of an internal combustion engine, which reservoir should be maintained at substantially a constant level. Utilizing suction of the engine, by means of a connection to the intake manifold thereof, air is drawn through the fuel so as to vaporize the fuel and mix the vaporized fuel with the fuel and air mixture from the main engine carburetor. While such auxiliary carburetors increase the efiiciency of the engine for shortterm operation, long-term operation causes an accumulation of heavy, substantially non-vaporizable fuel components in the small reservoir. This build-up of the non-vaporizable fuel components decreases the efliciency of the engine since unless the fuel in the auxiliary carlatent O buretor is vaporized, no new fuel enters the reservoir operation of a vehicle causes slashing of the fuel in the reservoir, the level varies due to the movement of the float of the float-operated valve.

According to the present invention, I have provided novel means for discharging a portion of the reservoir each time the engine to which the auxiliary carburetor is attached is stopped, so that there can be no accumulation of the heavy, non-vaporizable portions of the fuel. A novel type, gravity-operated valve is provided which permits the use of a very stable float arrangement, and, therefore, maintains a very constant level in the reservoir. An outlet for the auxiliary carburetor is interconnected to the engine gasoline line on the suction side of the pump and an outlet to the auxiliary carburetor is interconnected to the gasoline line on the pressure side of the pump to induce a circulation of gasoline through the auxiliary carburetor. The self-draining feature of the reservoir is automatic, wherein a certain portion of the reservoir is drained from the reservoir each time the engine to which it is connected is stopped and the instant the manifold pressure becomes less than the fuel pump suction through acceleration, there is an automatic change in gasoline in the reservoir.

Included among the objects and advantages of the present invention is an auxiliary carburetor, or vaporizer which is provided with an automatic draining device so as to prevent accumulation of substantially non-vaporizable fuel in the reservoir of the vaporizer. Novel valve means are provided which prevents draining of the reservoir during operation of the carburetor, and which may be utilized as a float-operated valve for precisely controlling the level of the fluid in the reservoir.

These and other objects and advantages of the invention may be readily ascertained by referring to the following description and illustrations in which:

Fig. 1 is a cross sectional elevation of an auxiliar carburetor according to the invention; 7

Fig. 2 is a top plan view of the auxiliary carburetor illustrated in Fig. l;

Fig. 3 is a schematic view of the installation of an auxiliary carburetor in the fuel system of an internal combustion engine;

Fig. 4 is a cross sectional view of a valve according to the invention in open position;

Fig. 5 is a cross sectional view of a valve of the invention in closed position; and

Fig. 6 is a cross sectional view of a valve according.

to the invention operated by a close-coupled float.

In the device illustrated in Fig. 1, a container 1, of substantially greater depth than diameter, has an upper flange 2 which provides a seat for a cover 3 having an outwardly extending flange 4. A gasket 5 between the two members seals the same. The tank 1 is provided with a drain 6 for use in draining the reservoir. The cover 3 is maintained in position on the tank 1 by means of bolt-and-nut assemblies, not shown, through a series of holes 7 in the flanges of the two devices. inlet fitting 10 extends through the cover 3, and a conduit 11 extends from the inlet to a float-operated valve 12, described in detail below, adjacent the bottom of the tank. A float 13 controls the operation of the valve, and provides means for maintaining a substantially constant level, indicated by dashed line 14, in the tank 1. An air inlet 15 having a screen filter 16 over its open end extends through the cover 3, and an interconnected air conduit 17 extends downwardly through the bottom of the tank. The lower end 18 of the tube 17 is bent at substantially right angles to the down pipe 17 and extends across the bottom of the tank. The tube portion 18 is perforated, through which perforations air bubbles to vaporize fuel in the tank. An angled connector 20 extends through the top 3 and is secured in place by means of a nut 21. The connector 20 opens into the top portion of the tank 1, and a conduit from the manifold of the engine is attached thereto for drawing vapors from the tank into the engine. An angled connector 24 extends through thecover and is interconnected with a down pipe 25 which is closed at its lower end by means of a valve 26. Valve 26 is similar to valve 12, which will be described below.

In operation the device is utilized on an internal combustion engine such as 30, illustrated in Fig. 3, and only a portion of which is illustrated. The tank 1 of the auxiliary carburetor is mounted in the engine compartment adjacent the main carburetor 34, and is interconnected from vapor outlet 20 through a vapor conduit 31 to a manifold spacer ring 33 mounted in between the carburetor 34 and the engine 30. A fuel inlet conduit 35, which is interconnected with fuel inlet 10, is connected by means of a T 36 into the fuel line 37 which extends from a fuel pump, shown in general by numeral 38, and the carburetor 34. A drain conduit 39 interconnected with the drain outlet 24 is connected to a T 40 in the main fuel line 41 between the vehicle tank, not shown, and the fuel pump 38.

On starting the engine 30, the suction of the manifold draws air from the tank 1 through the vapor conduit 31 subjecting the tank to a slight reduced pressure, and when An angle the level of the fuel in the tank is below the full mark 14, fuel is admitted into the tank through the line 35 from the conduit 37 between the pump and the carburetor. Under the influence of the reduced pressure air drawn through the air inlet 15 and subsequently through the perforated tube 18 and is bubbled through the fuel to vaporize the same. The vaporized fuel is drawn through the vapor conduit 31 and is mixed with the fuel and an mixture from the carburetor 34 at the uanlfold spacer The outlet valve 26 may have a smaller capacity than the inlet valve 14, and the force of the suction slde of the pump 38 is less than the pressure side, so there is a continuous circulation of gasoline through the auxihary carburetor. The level of gasoline in the tank 15 mamtained by the float valve 14,.and the recycled gasoline mixes with the gasoline from the supply tank keeping substantially fresh gasoline in tank 1.

The auxiliary carburetor operates automatically on the manifold suction, and the float-operated valve mamtains a substantially constant level in the auxiliary carburetor, during engine operation. When the engine is stopped, fuel in the main fuel line 41 from the vehicle fuel tank to the fuel pump 38 drains back into the tank since the fuel pump is always placed higher than the tank. The flowback of the fuel causes a suction or reducedpressure on line 39 opening valve 26 and a lowering of the fuel level in the reservoir to level 42 where the valve 26, by means of a side hole 43, starts passing air instead'of fuel. This drainback occurs each time the engine is stopped, so that a small amount of fuel, represented by the volume between the maximum fuel line 14 and the low fuel line 42, is withdrawn from the tank 1 so that there is no accumulation of the heavy, substantially non-vaporizable portions of the fuel.

The valve of the invention is illustrated in Figs. '4 through 6. The valve includes a housing 50 which 1ncludes a small passage terminating into a large outlet 52. The opposite end of the passage 51 includes a conical or flared inlet 53. The housing 50 includes threads 54 for engagement with an internally threaded conduit 55. A gasket 59 is placed on the housing 50 to insure a seal between the housing 50 and the threaded conduit 55. A valve stem 56 which is of smaller cross sectional dimensions than the passage 51 is freely reciprocally mounted in the passage 51. The stem 56 has a shallow groove 57 extending around its circumference adjacent one end thereof. A soft resilient material annular gasket or O-ring 58 is mounted in the groove 57. The outer diameter of the annulus 58 is slightly larger than the'diameter of the passage 51 so that the O-ring prevents the passage of the stem 56 through the passage 51 and seats in flared inlet 53. The valve illustrated in Fig. 4 is shown in the open position where the O-ring seal 58 is not seated on conical surfaces of the flared inlet 53. In closed position, Fig. 5, the O-ring seal 58 seals on the conical surfaces of the flared outlet 53 completely closing the passage 51 and preventing the passage of fluid therethrough. When used as a drain valvefor the outlet 24, a small hole 60 in the side of the housing in the enlarged outlet 52 may be provided to determine the low point of the fluid in the tank. The weight of thestem 56 maintains the valve in closed position until the suction from conduit 55 forces the stem and the O-ring seal off its seat and permits passage of fuel there-around.

In operation of the valve of Figs. 4 and 5, where the valve is placed on the drain outlet 24, the valve will remain in substantially closed position due to the weight of the stem 56 and the fuel in the line 25 above it. Even when the line 39 is empty as when the engine is initially started, fuel passing through the line 41 will trickle down through the line 39 and will substant'iallyfill the tube 25 to aid in holding the valve closed. Suction on line 39 raises the stem 56' opening the valve.

In the modification of Fig. 6 a float support 60- is mounted on the valve and is held in between the housing 50 and the threaded conduit 55 in position to support a float 13 thereon. The float 13 is mounted on a float support arm 62 which is pivotally mounted on pivot 61 which is secured to the float support 60. A float arm extension 63 extends beyond the pivot 61 in position to contact the valve stem 56. A float stop 64 is provided on the float arm 62 to determine the maximum rise of the float. The up and down movement of the float 13 opens and closes the valve 12, and since the fuel in fuel line 37 is under pressure the valve will remain closed until the level of fluid drops so that the float opens and holds the valve 12. This pressure acting on the valve plus the weight of the valve stem in seating against the conical surface 53 provides a very positive action valve. The float is limited in its upward movement by means of a stop 64 pressing against the housing 50 and is thereby limited in movement. The stop 64 on the bottom of the valve limits the movement of the float downwardly. As the vehicle travels along the road, the sloshing of the liquid moves the float up and down, and when the float lowers to a certain point the float arm extension 63 contacts the stem 56 opening the same and permits the entrance of more fuel into the reservoir. Since the valve is under pressure from the fuel in the line, there is slight delayed action of the valve, so that quick up and down movement of the float 13, caused by sloshing, will not keep the valve open thus preventing an excess of fuel in the tank. The simplicity of the valve of the present invention, whether it is used as a drain valve or as a fuel inlet valve, greatly increases the positive action of the vaporizer and maintains a substantially constant level therein. As a drain valve the action is positive, draining the tank to the correct level.

While the invention has been illustrated by reference to specific examples there is no intent to limit the invention to the precise details so described except insofar as set forth in the following claims.

I claim:

1. In an auxiliary carburetor arranged for connection to the intake manifold of an internal combustion engine and which has a small fuel reservoir through which air is bubbled to vaporize fuel under the influence of the suction of the main engine carburetor, the improvement which comprises a float controlled valve mounted in said reservoir, a fuel line interconnected to said float controlled valve and the main fuel line between the engine fuel pump and carburetor whereby fuel may be maintained at a predetermined level in said reservoir, an outlet for the fuel in said reservoir, a valve in said outlet arranged to permit withdrawal of fuel from said reservoir and prevent entrance of fuel into said reservoir, and means for connecting said outlet to the main fuel line of the vehicle on which it is mounted between the vehicle fuel tank and the vehicle fuel pump whereby there is a continuous recycling of fuel through the reservoir on engine operation and a reverse flow of fuel in the main fuel line withdraws a portion of fuel from said small reservoir through said outlet.

2. In an auxiliary carburetor arranged for connection to the intake manifold of an internal combustion engine and which has a small fuel reservoir through which air is bubbled to vaporize fuel under the influence of the suction of the main engine carburetor, the improvement which comprises a float controlled valve mounted in said reservoir, a fuel line interconnected to said float controlled valve and the main fuel line between the engine fuel pump and carburetor whereby fuel may be maintained at a predetermined level, in said reservoir, an outlet conduit extending into the fuel in said reservoir, a valve in said conduit arranged to permit withdrawal of fuel from said reservoir by suction and prevent entrance of fuel into said reservoir, and means for connecting said outlet into the main fuel line of the vehicle on which it is mounted between the vehicle fuel tank and the vehicle fuel pump whereby there is a continuous recycling of fuel through the reservoir on engine operation and a reverse flow of fuel in the main fuel line creates a suction in said conduit and withdraws a portion of fuel from said small reservoir.

3. In an auxiliary carburetor arranged for connection to the intake manifold of an internal combustion engine, which auxiliary carburetor has a small fuel reservoir through which air is bubbled to vaporize fuel under the influence of suction of the main engine carburetor, the improvement which comprises a float controlled valve mounted in said reservoir, a fuel line interconnected to said float controlled valve and the main fuel line between the engine fuel pump and carburetor whereby fuel may be maintained at a predetermined level in said reservoir, an automatic drain device for the small reservoir of the auxiliary carburetor when the engine to which it is attached is stopped which includes an outlet for said small reservoir, a gravity closing and suction opening valve for said outlet arranged to permit withdrawal of fuel from said reservoir and prevent the entrance of fuel into said reservoir, and means for connecting said outlet to the main fuel line of a vehicle on which the device is mounted between the vehicle fuel tank and the engine fuel pump thereof, whereby there is a continuous recycling of fuel through the reservoir on engine operation and a reverse flow of fuel in said main fuel line withdraws a portion of the fuel in said reservoir.

4. In an auxiliary carburetor arranged for connection to the intake manifold of an internal combustion engine which auxiliary carburetor has a small fuel reservoir through which air is bubbled to vaporize fuel under the influence of suction of the main engine carburetor, the improvement which comprises a float controlled valve mounted in said reservoir, a fuel line interconnected to said float controlled valve and the main fuel line between the engine fuel pump and carburetor whereby fuel may be maintained at a predetermined level in said reservoir, an automatic drain device for the small reservoir of the auxiliary carburetor when the engine to which it is attached is stopped which includes an outlet conduit extending downwardly into said small reservoir, a gravity closing and suction opening valve interconnected in said outlet conduit arranged to permit withdrawal of fuel from said reservoir and prevent the entrance of fuel into said reservoir, and means for connecting said outlet conduit to the main fuel line of a vehicle on which the device is mounted between the vehicle fuel tank and the engine fuel pump thereof, whereby there is a continuous recycling of fuel through the reservoir on engine operation and a reverse flow of fuel in said main fuel line creates a suction in said conduit and withdraws a portion of the fuel in said reservoir.

5. In an auxiliary carburetor arranged for connection to the intake manifold of an internal combustion engine which auxiliary carburetor has a small fuel reservoir through which air is bubbled to vaporize fuel under the influence of suction of the main engine carburetor, the improvement which comprises a float controlled valve mounted in said reservoir, a fuel line interconnected to said float controlled valve'and the main fuel line between the engine fuel pump and carburetor whereby fuel may be maintained at a predetermined level in said reservoir, an automatic drain device for the small reservoir of the auxiliary carburetor when the engine to which it is attached is stopped which includes an outlet conduit extending downwardly into said small reservoir, a gravity closing and suction opening valve interconnected in said outlet conduit arranged to permit withdrawal of fuel from said reservoir and prevent the entrance of fuel into said reservoir, means interconnected with said conduit for predetermining the level of fuel remaining in said reservoir, and means for connecting said outlet conduit to the main fuel line of a vehicle on which the device is mounted between the vehicle fuel tank and the engine fuel pump thereof, whereby there is a continuous recycling of fuel through the reservoir on engine operation and a reverse flow of fuel in said main fuel line creates a suction in said conduit and withdraws a portion of the fuel in said reservoir.

References Cited in the file of this patent UNITED STATES PATENTS 481,761 Hughes Aug. 30, 1892 1,586,405 Burge May 25, 1926 1,863,195 Ensign June 14, 1932 2,358,228 Hoof Sept. 12, 1944 2,550,313 Tucker Apr. 24, 1951 2,591,514 Courtot Apr. 1, 1952 2,687,711 Chambers Aug. 31, 1954 2,702,694 Featherston Feb. 22, 1955 

